


flames

by doitforthecarstairs



Category: The Last Hours Series - Cassandra Clare, The Shadowhunter Chronicles - Cassandra Clare
Genre: Friendship, Other, WLW MLM and Aroace solidarity :D
Language: English
Status: Completed
Published: 2021-02-27
Updated: 2021-02-27
Packaged: 2021-03-18 23:49:45
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 745
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29741781
Author URL: https://archiveofourown.org/users/doitforthecarstairs/pseuds/doitforthecarstairs
Summary: Thomas, Lucie and Christopher are spending some time together in the Fairchilds’ lab when the word romance comes up.February 27: love
Relationships: Christopher Herondale & Thomas Lightwood, Lucie Herondale & Thomas Lightwood, Thomas Lightwood & Lucie Herondale & Christopher Lightwood
Kudos: 14
Collections: Chain of Iron countdown





	flames

**Author's Note:**

> I love writing platonic relationships if you couldn't tell before :D
> 
> Trigger warnings for slight mention of explosions.

When Thomas had arrived, the Fairchilds’ laboratory was surprisingly quiet.

But of course, silence never lasted long with his cousins in there.

_Boom._ He sighed; it sounded less bad than the previous explosions, at least. Thomas heard Lucie giggle as he got into the room filled with equipment most people couldn’t begin to understand. Christopher’s face was covered in ashes, but Lucie seemed too busy laughing to hand him a towel.

“Good to know you two started destroying things without my supervision.” Thomas leaned against the door, making himself present. Christopher looked up startled and Lucie offered him a seat next to her.

“We’re sorry, Tom, we’ll wait for you before we try to explode someone’s house next time.”

Thomas huffed light-heartedly before walking towards his cousins. “Thank you, Luce, how considerate of you.” He messed Christopher’s hair and passed him a towel to clean his face, but he waved him off. 

“I’ll never be a real scientist if I’m not willing to explode my face.”

“I don’t think that is how science works, Kit.” Lucie said, writing something down. “Oh, yes! Now that Thomas is here, you two can help me.”

Thomas waited for her to continue. She clicked her tongue a couple times and hit her writing machine with her fountain pen before remembering she was supposed to explain what she meant. “I’m adding a new romantic storyline in The Beautiful Cordelia, and I need advice in writing about two people falling in love.”

“Why– why do you assume I’d be able to help?” Thomas cleared his throat and looked away. “Ask Christopher, he was the one who enchanted a demon.”

“Kit?” Lucie called, not before giving Thomas a questioning look. 

Christopher seemed confused for a moment before his face lit up. “I love lemon tarts! Does that count as falling?”

“If you really love them, then why not?” She smiled at her cousin before turning back to Thomas. “But I need more on-point advice. Please, Tommy?”

“I’m–” he swallowed. “Sure. What do you want to know?” Then, as a second thought, he added: “I can’t promise accuracy.”

Lucie clapped. “Wonderful! You’ve been to Paris, haven’t you?”

Thomas grunted. “I have.”

“The city of love. One of my characters spent part of his life in France, and- you look nervous, Thomas. Do you need some air?” 

“I need you to change the subject” Thomas stared at Christopher’s hands while he poured a red liquid into an empty test tube. His cousin seemed distracted from their conversation, devoting his attention to something that was likely going to explode. One less person to notice how hard Thomas was blushing.

“Oh.” Lucie’s blue eyes were wide open. _“Oh.”_

“ _Not_ oh.” 

His protest didn’t stop Lucie’s face from lighting up. “I’m just wondering if you met someone there.” _Curse her mischievous smile,_ Thomas thought. But there wasn’t getting away from Lucie’s questions now. “A beautiful lady, or perhaps a handsome gentleman?”

“There is no one,” Thomas muttered, but his mind kept reminding him of his beautiful dark eyes, and he wondered what his genuine laugh would sound like… He cleared his throat and repeated: “There is no one.”

Lucie opened her mouth to say something else, but Thomas interrupted her. “What about you, Luce? You’ve been with your head in the clouds since the Carstairs’ arrival. I wonder why that would be.” 

“So have you!” Thomas had to admit he had dug his own grave, but that wouldn’t stop him from blushing. “Is there something else we need to discuss, Tommy?”

They blinked at each other, their faces red, before awkwardly looking away. “This is- a dangerous territory,” Thomas mumbled.

“Agreed.”

“Do you know what is _not_ a dangerous territory?” Christopher raised his head from his experiment, most likely clueless of the context. He raised his test tube filled with a bubbling liquid. “Turning things purple!” Then he gasped, turning his amazed expression to look at his cousins. “Turning lemon tarts purple.”

Thomas laughed, both from relief at the interruption and from affection for his family. He took the tube test out of his cousin’s hand:

“I’d prefer it if we ate the lemon tarts first. _Then_ we can try to explode uncle Henry’s laboratory again.”

“Sounds like a plan!” Lucie got up and took the ashes out of her skirt. Christopher followed her without bothering to clean his face. 

Thomas sighed, not for the first or last time that day. He really, really loved his family.

**Author's Note:**

> I'm on Tumblr under the same name!


End file.
